functional gain
Difference between unaided and aided hearing thresholds, representing the effective amplification provided by hearing aids.
Full Definition
Functional gain quantifies hearing improvement achieved through amplification by comparing unaided and aided pure-tone thresholds at each frequency. Calculated as the difference between unaided and aided thresholds (unaided minus aided), functional gain demonstrates how much amplification benefit the hearing aids provide across the frequency range. This measurement validates hearing aid fittings against prescriptive targets and helps determine if amplification goals have been met. Functional gain differs from insertion gain, which measures amplification in the ear canal using probe microphones rather than behavioral responses.
Usage
Usage note: Express as 'X dB functional gain' and always specify frequency; distinguish clearly from insertion gain measurements.
In Context
- "Functional gain measurements showed 25 dB improvement at 2000 Hz with the new hearing aids." — Hearing aid verification report
- "The patient's functional gain fell short of prescribed targets, requiring programming adjustments." — Amplification follow-up notes